@Patrick Thank you very much for your advised. My propose is just provided another way to get result, the reason to use Data Validation node because jwhite want to descending column #5 if there're more duplication values in 4 keys.
... View more
Let try "Sort" node to order 5 keys(#5 key is the descending value) which you mention, then use "Data Validation" node to reject duplicate row by 4 keys (select option: Move all but one row to error table). hope it can help you. 🙂
... View more